Elliptic spring



(No Model.)

E. SPAULDING.

I ELL'IPTIG SPRING. N0. 352,014. 4 Patented Nov. 2, 1886. I

Inn

" I. 'iNVENTOR ey gg y BY fyfaya ATTORNEY UNITED STATES PAT NT OFFICE.

NORMAN E. SPAULDING, OF BROOKLYN, NEW YORK.

ELLIPTIC SPRING.

SPECIFICATION forming part of Letters Patent No. 352,014, dated November2, J 886.

Application filed April 24, 18812. Renewed May 19, 1884. Serial No.132,085. (No model.)

Springs, of which the following is a specifica tion. 1

This invention relates to the elliptic springs the plates of which aremade in concavo-convex form in cross-section; and it consists in makingthe coils at theend of the springs, for

forming the edges for the connecting-bolts, of the same concavo-convexform of the plates as the rest, instead of the flat extensions, asheretofore, wherebythe advantage of the superior strength imparted tothe springs by reason of the said concavo-convex form is available inthe eye part aswell as in the rest.

Springs made of plates of the form described, and said plates arrangedin the spring so that the tension is sustained on the middle web of theplates and the compression on the edges of said plates, are found'inpractice to possess about twice the power to sustain the load thatsprings made of the ordinary flat plates have; but as such springshaveup tor-this time been made with the main plate flattened just where thecoil for the eye begins, so that in that part they are no stronger thanthe fiat plate-springs are, the great advantage of concavo convex formof the rest of the spring has notbeen as available as is desirable,although the defect might be remedied by thickening the plates where theshape changes from the curved to the flat form. That is not practicable,because in the manufacture of the plates it is desirable to roll themout in long strips and cut them into the short pieces of differentlengths required for springs; hence it is desirable to continue the saidcurved form of the plates throughout the coil for the eye for the boltthat connects the two halves of the spring, ..and thus invest the saidparts with about the same strength as the rest of the plate in which theeye is formed, as hereinafter more fully described, reference being madeto the accompanying drawings, in which I Figure 1 is a side elevation ofa portion of an elliptic spring of the kind above described, and sectionof the connectingbolt, and a washer employed in carrying out theinvention, the

I eye being in this case formed by a half-coil in each plate, the endsof the plates meetingand butting together, and the plates being securedby the collars of the Washers shown in Fig. 4,

the section'of Fig. 1 being taken on line a: w of said Fig.4. Fig. 2 isa similar view of a spring of the kind described, the eye being formedby coiling the ends of the plates completely around the bolt, or nearlyso, one of 6c The said plates being outside of the other. section of thewasher and connecting-bolt is taken on line y y of Fig. 3. Fig. 3 is asection on line 2 z of Fig. 2. Fig. 4 is a section on line a a of Fig.1, and Fig. 5 is a detail of the washers of Fig. 4.

A represents the plates of the spring, which, as before stated, are madein concavo-convex form in cross section, and arranged in the spring,with the convex sides B of said plates facing towardthe longitudinalaxis of the ellipse. The said form of the plates is more clearly shownin the cross-section of them in Figs. 3 and 4. The said concavo-convexforms are produced by means ofthe dies of a drophammer or other press,in which the plates are struck while in a heated state. The diesheretofore employed for this purpose have been so formed that theconcavo-convex form termi nates at O, leaving the rest of the plateflat, to

make the plain cylindrical eye for a plain bolt,D. It is this fiat partthatl'ails when the spring is loaded to the capacity of the rest of thespring, and therefore I continue the same curved form of the platearound the boltD,

thus extending the curved form of the plate to where the plate findsrest and support, that largely relieves it of supporting the load by itsown unaided strength, which support is in this case afforded by theconical hubs F, which I makeon or may apply separately with the washersG H, used on the bolt D at the edges of the springs, the said conicalhubs being to fill the flaring portions of the eyes for the bolt and toafford the required support to the plates.

When the plates extend only half around ICO the bolt, as in Figs. 1 and4, I make the washers G H with a flange, I, to overlap the edges of theplates and more securely hold them, the flanges being notched, as shownin Fig. 5, where the plates branch away from the eyes. These flangedwashers are also applicable to springs having the eyes made of flatcoiled plates, the washers being made without the hubs. This form of theeye is preferred when it may be thought necessary to construct thespring so that it can be taken apart; but when it is not required to doso the arrangement of Figs. 2 and 3 will be the best.

The invention applies as well to semi-elliptic springs having a bolt, D,in an eye of the end for any purpose.

lVhat I claim, and desire to secure by Letters Patent, is

1. An elliptic spring the plates of which are of concavo-eonvex form incross section, and arranged with the convex sides of the plates facingthe longitudinal axis of the ellipse, the parts of the plates of whichthe coils for the eyes for the connecting-bolts are formed being thesame in form as the body of the plates, said form being extendeduniformly throughout the plates, and the eyes for 2 5 the connectingbolts, substantially as described.

2. The combination of washers having conical hubs F with ellipticsprings the eyes of which are formed of plates of coneavo-convcx 0 formin cross section, substantially as described.

3. The combination of washers G H, having flanges I, with the eyeboltsand the bolt-eyes of elliptic springs, said flanges overlapping 5 theedges of the coils of the plates forming the eyes, substantially asdescribed.

NORMAN E. SPAULDING.

Witnesses:

WV. J. MORGAN, S. H. MORGAN.

